1. Field of the Invention
The invention relates to a method and device for the application of liquids to plants in agricultural stands with the aid of portable field-spray equipment by the utilization of drag hoses at the distributor elements attached to the regular connection pieces of application equipment.
2. Description of the Prior Art
In agriculture in general, the application of fertilizers and the metering of plant protection and pest control is performed not only prior, simultaneously with, or shortly after the sowing, but it is also done during advanced stages of vegetation. The repeated fertilization is particularly important for grains and for rape.
For the application of liquids it is necessary to drive portable field-spray equipment through the stands while applying liquids such as plant protection and pest control liquids as well as liquid fertilizers. The liquids to be applied therefore secure the quality of the yield and increase the volume of the yield.
The liquids must be applied in such a manner that no overdose is applied, nor should some of the areas be given an inadequate supply, lest the particularly sensitive parts of the plants be endangered.
Depending upon their grown height and their stage of development respectively, the plants are particularly sensitive at particular parts, to the active liquids. For instance, in grains and grasses at the top leaves and set-up crop, or at the green leaves of rape.
Other parts of these plants react indifferently, and there are observations to the effect that slight etching might even stimulate growth.
These facts point up the necessity of an application of liquids to such stands in a manner which will ascertain that the organs essential for the formation of the crop will not be injured.
It is known that a spray jet of liquid fertilizer may cause minor etching of the plant if it hits the plant with a low impact and in a careful manner.
Neither is it new that minor etching occurs whenever the liquid fertilizer is distributed in the form of coarse droplets. Whenever the spectrum of droplets emerging from the jets consists mostly of finer droplets, a markedly increased wetting is registered. In the case of fertilization with liquid fertilizer, one can observe extended damage to the plants. In order to achieve a distribution of coarser droplets, the so-called drop pipe was invented which is attached to the usual spray rods by connection pieces at a distance of one half meter and with total lengths of 10 to 20 meters. Usually, these drop pipes have 8 bores for each 50 cm, i.e. the droplet paths run in a distance of 6.25 m.
It is the disadvantage of this equipment that it is unwieldy in operation. It also happens relatively frequently that the drop pipes break; this applied in particular to the outside pipes whenever the rods sway, for instance, when turning around or driving in curves, or in an uneven terrain.
The idea suggests itself that the damage would be less whenever active liquids in lower concentrations are used. In the example described in the following, a ratio of 1:2.6 was used.
The spray angle out of the distributing equipment has a great influence on the localization of the major part of the liquid in various zones of the plants. The application of liquid fertilizer by means of distributing means which give the spray jet a horizontal flight path, cause greater etching than a vertically emerging jet.
Considering the above, fan jet nozzles were developed such as the nozzle 150/03 and nozzle 110/10. In this case, 150 or 110 respectively indicate the spray angle in angle degrees, while the numbers behind the slash indicate information by the manufacturer relating to the flow-rate. Given these characteristics, the fan jet nozzle 150/03 yields a spectrum of fine droplets, while the nozzle 110/10 has a size of droplets in the range of coarser drops.
The Flood Jet-nozzle provides an almost horizontally emerging jet of liquid. In this nozzle, the liquid hits a distributor disc after coming from a vertical bore. The improvement hoped for with the use of this nozzle, however, is limited inasmuch as the greater part of the liquid to be distributed comes to rest on the leafy roof of the stands. This causes damage. The less sensitive portions of the plants and those parts which, under certain circumstances would even profit from such damage, raising their yield and their quality, are hardly ever hit during the use of a Floodjet nozzle.
In the following table, the described nozzle systems are compared, using 60 kg N/ha in the form of AHL for the fertilization of autumn-sown wheat (Types: Diplomat, Disponent, Maris-Huntsman and Vuka) with a corresponding application of KAS prior to sowing. A classification (with grades 1=very good to 9=very bad) was made, and yields were observed. These were given as relative figures to the KAS-yield=100.
TABLE 1 ______________________________________ Test No. Type Classification Yield % ______________________________________ 1 KAS 1.0 100 2 Drop pipe (undiluted) 1.0 93 3 Drop pipe (diluted 1: 2.6) 1.0 99 4 Fanjet nozzle 150/03 2.5 95 5 Fanjet nozzle 110/10 1.0 100 6 Floodjet 3.5 94 ______________________________________
It has been shown that the depth of etching and the loss in yields are not parallel to each other. Thus, the Floodjet nozzle (6) in spite of rather high degrees of etching, yields higher yields than the drop pipe with an undiluted application of the AH - solution (2). On the other hand, yield losses have been observed when there were practically no damages by etching to be observed (see Test No. 2).